Does it matter what President Obama calls his health-care reform law? That question arises because he’s seemed to shift his references in recent days. Previously, he’d embraced the label “Obamacare,” saying it reflected the fact that he did indeed care about uninsured Americans. But as Politico notes, that term now seems to have fallen into White House disfavor.

Instead, the administration appears to again prefer “Affordable Care Act” (ACA), which reflects the law’s full name, “Patient Protection and Affordable Care Act.” That’s how Mr. Obama has been referring to it in public. Democratic Party talking points now emphasize the “Affordable Care Act” phrase.

“Calling it the Affordable Care Act has advantages for Democrats seeking to defend health care reform while still criticizing the bungled White House rollout,” Politico’s Reid J. Epstein wrote last week.

Think this is just a minor tweak, or maybe the media are reading too much into the president’s rhetoric? We’d say that’s highly unlikely. Administrations poll voters on the use of one word or another all the time. Indeed, that’s a technique used throughout US politics.

“It’s a truism in politics that labels matter,” Gallup’s editor in chief Frank Newport writes in his blog on survey techniques.

To show this, Gallup ran a poll that tested different ways to refer to the health-care law. The results showed that the name had at least a marginal effect on respondents’ opinions.

Gallup’s test went like this: Some people were asked whether they approved of the Affordable Care Act that had been signed into law by Obama. Some were simply asked if they liked the 2010 law that had changed the US health system. A third variant asked if respondents liked “Obamacare.” A fourth asked if they liked the “Affordable Care Act,” with no mention of Obama at all.

That last version polled the best. Using that question, Gallup found that 45 percent of respondents approved of the ACA and 49 percent disapproved.

In contrast, the version that referred only to “Obamacare” polled worst. Only 38 percent approved of Obamacare per se, while 54 percent of respondents disapproved.

“These results suggest that the Obama administration’s decision to shift to Affordable Care Act as their label of choice and to avoid using Obamacare would appear to be a branding strategy that works in the administration’s interest,” Mr. Newport writes. “Clearly, all else being equal, the words ‘Affordable Care Act’ engender a modestly more positive reaction than the term Obamacare.”

This shouldn’t be that surprising. Presidents can be polarizing. Lots of political science research shows that personal involvement on the part of a US chief executive makes political opponents view an issue in a more negative light.

We’d also note that even the best-case scenario in that Gallup poll shows that opinion of the ACA is more negative than positive. That probably reflects both the public’s long-felt wariness about the law and the continued negative publicity from its problematic rollout.